[logifail]

Airlines don't have to honour mistake fares, and this was definitely one of those. FWIW, I got away with it.

If you miss a flight and the airline determines you booked it (typically as a return or hidden city leg) without ever intending to fly it, they will very definitely try to make life difficult for you.

Try short-checking a bag to LON on a NYC-LON-Europe booking with AA or BA, they will refuse. They're worried you booked to Europe for a lower price but intended all along to leave in LON.

There are ways round this "rule", too. If you know what you're doing.